Sealing bellows with snap-on connection

ABSTRACT

A sealing bellows is provided having a jacket ( 1   b ) arranged between first and second edges ( 1   a   , 1   c ) of the sealing bellows. The edges ( 1   a   , 1   c ) of the sealing bellows are sealingly in contact with components in the assembled state of the sealing bellows ( 1 ). At least a first edge ( 1   a ) of the sealing bellows has radially inwardly pointing teeth ( 3   a ), which engage a contour of a component or a housing ( 2 ) of a ball and socket joint to form a snap connection.

FIELD OF THE INVENTION

[0001] The present invention pertains to a sealing bellows for ball andsocket joints, especially for motor vehicles, the sealing bellows havinga jacket arranged between a first edge and a second edge of the sealingbellows, wherein the edges of the sealing bellows are sealingly incontact with components in the assembled state of the sealing bellows.

BACKGROUND OF THE INVENTION

[0002] Packings or sealing systems, also called rubber bellows, arefrequently used in the area of chassis engineering. They are located,e.g., in the area of ball and socket joints or drive axles. The packingsor rubber bellows have the function of a seal, which separate the innerfunctional area of, e.g., a ball and socket joint, from outside effectsduring both rotary movements and tilting movements. As a result,additional wear, e.g., in the form of friction and corrosion, isavoided. The edges of the bellows are usually provided with additionalstraining rings, which apply pressure to the mostly metallic components,e.g., the housing of a ball and socket joint or a pivot, so that thesealing bellows is secured against slipping off in the axial direction.These sealing bellows or packings usually also have additional collarsprojecting inwardly in the radial direction, which extend behindprojections on the components and thus ensure an additional axialfixation in addition to the straining ring. Such sealing bellows of thisclass for ball and socket joints are known from DE-OS 1 575 708, DE-OS 1168 717 as well as DE-PS 925 328.

[0003] The drawback of the sealing bellows or packings of this kind isthat an additional straining ring is always needed for the secure axialfixation of the sealing bellows, so that not only are additional partsneeded, but the assembly effort is also relatively high as a result.

SUMMARY OF THE INVENTION

[0004] The object of the present invention is to provide a sealingbellows that avoids the above-described drawbacks.

[0005] According to the invention, a sealing bellows is provided with ajacket arranged between a first edge and a second edge of the sealingbellows. The edges of the sealing bellows are sealingly in contact withcomponents in the assembled state of the sealing bellows. A first edgeof the sealing bellows has radially inwardly pointing teeth. The presentinvention also comprises the use of the sealing bellows according to thepresent invention for ball and socket joints.

[0006] The sealing bellows according to the present invention has theadvantage that no straining ring is needed for the sealing and durablefastening of the bellows to a component. The sealing bellows can beadvantageously pushed easily over a component with its teeth, the teethbeing bent over due to their shape and pivoting into correspondingrecesses of the component. The teeth advantageously have the shape ofsawteeth, so that the teeth can be bent over in one direction only. As aresult, the sealing bellows can slip off from the componentunintentionally only if a force that may possibly destroy the bellows isapplied.

[0007] The teeth may be made in one piece with the sealing bellows.However, it is also possible for the teeth to be injection molded in onepiece with the sealing bellows, e.g., by means of a two-componenttechnique. It is also possible for the sealing ring carrying the teethto be injection molded with or bonded to the sealing bellows.

[0008] By providing a plurality of circular rows of teeth, a very goodsealing is achieved between the sealing bellows and the component. Dueto the absence of the straining ring in the area of the teeth, a dynamicconnection is obtained, which is advantageously designed as a snapconnection. It can be guaranteed by the advantageous embodiment of thecomponent that the edge of the sealing bellows, which carries the teeth,can no longer move in the axial direction, i.e., in the direction of thepivot.

[0009] It is obviously possible for each edge of the sealing bellows tohave corresponding teeth, so that a straining ring is no longer neededfor both sides. However, it is, of course, also possible for an edge ofthe sealing bellows to be secured statically against unintentionalseparation by means of a straining ring. Thus, this edge of the sealingbellows may have sealing lips, which come sealingly into contact withthe component due to the action of the force of the straining ring. Theedge of the sealing bellows advantageously has an outwardly pointing,circular groove for receiving the sealing ring for this purpose, so thatthe sealing ring cannot unintentionally slip off the sealing bellowsafter the assembly.

[0010] All plastics may be generally considered for use as the materialfor the teeth or the snap hook connection. However, thermoplastics,which possess good tribological and elastic properties, are preferred.

[0011] Possible embodiments of sealing bellows according to the presentinvention and ball and socket joints according to the present inventionwill be explained in greater detail below on the basis of drawings. Thevarious features of novelty which characterize the invention are pointedout with particularity in the claims annexed to and forming a part ofthis disclosure. For a better understanding of the invention, itsoperating advantages and specific objects attained by its uses,reference is made to the accompanying drawings and descriptive matter inwhich preferred embodiments of the invention are illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a cross-sectional view of a ball and socket jointprotected by means of a sealing bellows according to the presentinvention;

[0013]FIG. 2 is an enlarged detail of FIG. 1;

[0014]FIG. 3 is a cross-sectional view of another possible embodimentwith an optional straining ring;

[0015]FIG. 4 is a cross-sectional view of another possible embodimentwith an additional tooth element, which is arranged on a component,e.g., a ball and socket joint housing; and

[0016]FIG. 5 is another possible embodiment with a ring made of metal orplastic, which is incorporated by vulcanization or is extrusion coated.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Referring to the drawings in particular, FIGS. 1 and 2 show thedetail of a ball and socket joint, comprising a housing 2, whichaccommodates a socket, not shown. A ball pivot 4 with its joint ball,not shown, is located in the socket of the housing 2. The ball andsocket joint is sealingly enclosed by a sealing bellows 1. The sealingspace is enclosed by the packing and the jacket 1 b, and the two edges 1a and 1 c of the sealing bellows are sealingly in contact with thehousing 2, which consists mostly of metal, and the pivot 4. The edges laand 1 c of the sealing bellows are made in one piece with the jacket 1b. The edge 1 a of the sealing bellows has a cylindrical inner surface,around which a sealing ring 3 is prepared by injection, bonded ortacked. On its radially inwardly facing side, the sealing ring 3 hasteeth 3 a extending in a circular pattern, which cooperate with thelikewise circularly extending teeth 2 a of the housing 2. The teeth 3 aof the sealing ring 3 are sawtooth-shaped, so that the sealing bellows 1can be pushed over the housing 2 in the direction of the arrowrelatively without problems, but it cannot unintentionally slip offsame. The teeth 2 a of the housing 2 are arranged on a collar-likeprojection 2 b of the housing, and the teeth 2 a point radiallyoutwardly. The housing 2 forms a limitation with the wall 2 c arrangedat the collar-like projection 2 b, and the limitation prevents the teeth3 a from being unintentionally displaced farther in the direction of thearrow in the assembled state. The sealing ring 3 as well as the edge 1 cof the sealing bellows are made of an elastic material, as a result ofwhich a pretension can be achieved in the radial direction, which allowsthe teeth of the sets of teeth to firmly engage each other. Due to thesawtooth structure, the teeth act like a snap connection. The other edge1 c of the sealing bellows has sealing lips 1 c′, which are sealingly incontact with the surface 4 a of the pivot 4. A sealing ring 5 is locatedin a correspondingly shaped, circular groove 1 c″ of the edge 1 c of thesealing bellows and generates a centripetal pressing force for thesealing lips 1 c′, so that reliable sealing is obtained between thepivot 4 and the sealing bellows 1 against moisture and dirt. The jacket1 b of the sealing bellows is likewise made of an elastic material, sothat the pivot 4 and the housing 2 can move in relation to each other.

[0018]FIG. 3 shows an optional straining ring 7, which applies anadditional force in the centripetal direction to the sealing teeth 3 a,2 a. As a result, stronger sealing is achieved by the teeth meshing witheach other more strongly. It is, of course, possible for the edge 1 a ofthe sealing bellows to have a circular groove for receiving and securingthe straining ring 7 in the axial direction on its radially outwardlypointing side. The additional straining ring 7 is used to furtherimprove the sealing and does not represent a turning away from theoriginal idea of the invention.

[0019]FIG. 4 shows another alternative embodiment, in which anadditional sealing ring 8 is arranged at a projection 2 b of the housing2. With its radially inwardly pointing jacket surface, the sealing ring8 is in contact with the projection 2 b. The projection 2 b may form acircular groove, in which the additional sealing ring 8 can be seatedsecured in the axial direction. The sealing ring 8 may be optionallybonded, welded or tacked to the housing 2. However, it is also possiblefor the sealing ring 8 to be prepared by injection molding orvulcanization in one piece. On its radially outwardly pointing side, thesealing ring 8 has circular teeth 8 a, which cooperate with the teeth 3a of the sealing bellows 1. The sealing ring 8 may be made, e.g., ofmetal, rubber or plastic, especially a thermoplastic elastomer (TPE).

[0020]FIG. 5 shows another design of the embodiment according to FIGS. 1and 2, in which the sealing ring 3 has a ring 9 incorporated byinjection molding or vulcanization. The ring 9 may be, e.g., a metalring for reinforcement.

[0021] It applies to all the above-described exemplary embodiments thatthe teeth may be greased. It is advantageously achieved hereby that thesealing bellows 1 can be pushed more easily over the housing 2 becauseof the reduced friction. In addition, better sealing action is achievedhereby. However, because of the teeth, the grease has no adverse effecton the locking of the teeth in the assembled state.

[0022] It also applies to all the above-described exemplary embodimentsthat the teeth are preferably made by means of plastic as the material,and that the sealing bellows is made of rubber. It is, of course, alsopossible to select other combinations of materials if this is necessaryfor the particular intended use.

[0023] While specific embodiments of the invention have been shown anddescribed in detail to illustrate the application of the principles ofthe invention, it will be understood that the invention may be embodiedotherwise without departing from such principles.

1-23 (Canceled)
 24. A sealing bellows, comprising: a jacket arrangedbetween a first sealing bellows edge and a second sealing bellows edge,said first edge being sealingly in contact with a component in theassembled state of the sealing bellows and said second edge beingsealingly in contact with a component in the assembled state of thesealing bellows; and inwardly radially inwardly pointing teeth providedat said first edge.
 25. A sealing bellows in accordance with claim 24,wherein the teeth are sealingly seated in a corresponding outer contourof the component in the assembled state.
 26. A sealing bellows inaccordance with claim 24, wherein the teeth are sawtooth-shaped withoblique flanks pointing in a direction in which the sealing bellows ispulled over the component.
 27. A sealing bellows in accordance withclaim 24, wherein the sealing bellows is made in one piece with theteeth from one material.
 28. A sealing bellows in accordance with claim24, wherein the teeth are formed by a sealing ring that is injectionmolded, tacked or bonded on the first edge of said the sealing bellowsor directly on the jacket.
 29. A sealing bellows in accordance withclaim 28, wherein the sealing ring has a ring made of plastic or metal,said ring being seated in the sealing ring.
 30. A sealing bellows inaccordance with claim 28, wherein said sealing ring is made of rubberand said ring made of metal or plastic is incorporated by vulcanization,or said sealing ring is made of metal and said ring made of metal orplastic is incorporated by injection molding.
 31. A sealing bellows inaccordance with claim 28, wherein said first edge of the sealing bellowshas a circular cross section, wherein an internal diameter of said firstedge of the sealing bellows and of said sealing ring is selected to besuch that the pretension of the material of the sealing bellows or ofthe material of the sealing ring sealingly presses said teeth into thecorresponding outer contour of the component in a pushed-over andassembled state.
 32. A sealing bellows in accordance with claim 24,wherein each of said first edge and said second edge have teeth, whichcooperate with corresponding surface contours of the componentscooperating with the sealing bellows.
 33. A sealing bellows inaccordance with claim 24, wherein said teeth form a sealing snapconnection together with a corresponding outer contour of the component.34. A sealing bellows in accordance with claim 24, wherein the teeth aremade of plastic, rubber or TPE.
 35. A sealing bellows in accordance withclaim 24, wherein the sealing bellows is made of plastic, rubber or TPE.36. A sealing bellows in accordance with claim 24, wherein said secondedge has a circular groove for receiving a straining ring on a secondedge side facing away from the component.
 37. A sealing bellows inaccordance with claim 24, wherein said second edge has sealing lips. 38.A sealing bellows in accordance with claim 24, further comprising astraining ring applying force said first edge of the sealing bellowsradially inwardly.
 39. A ball and socket joint for motor vehicles, theball and socket joint comprising: a housing with a surface contour; aball pivot which can be pivoted in the housing and/or is mountedrotatably in said housing; a sealing bellows a jacket arranged between afirst sealing bellows edge and a second sealing bellows edge, said firstedge having radially inwardly pointing teeth cooperating said surfacecontour of said housing, wherein said surface contour corresponds to acontour of said teeth.
 40. A ball and socket joint in accordance withclaim 39, wherein the second edge of the sealing bellows is sealingly incontact with the ball pivot by means of a straining ring or is connectedwith the first edge of the sealing bellows via a jacket area.
 41. A balland socket joint in accordance with claim 39, wherein said surfacecontour is likewise formed by teeth, wherein the two sets of teeth aresawtooth-shaped, wherein the oblique flanks of the teeth of the sealingbellows point in a direction of a direction of assembly of the sealingbellows and the oblique flanks of the teeth of the housing pointopposite the direction of assembly of the sealing bellows.
 42. A balland socket joint in accordance with claim 39, wherein said surfacecontour corresponding to a contour of said teeth includes housing teetharranged radially outwardly at a projection extending into the sealingbellows, wherein the housing wall adjoining the projection limits themovement by which the sealing bellows is pulled over the housing.
 43. Aball and socket joint in accordance with claim 42, wherein said housinghas a projection protruding into the sealing bellows and carrying anadditional sealing ring, which has radially outwardly pointing circularteeth forming said surface contour corresponding to a contour of saidteeth and cooperating with said teeth of said sealing bellows.
 44. Aball and socket joint in accordance with claim 43, wherein theadditional sealing ring is made of plastic or TPE.
 45. A ball and socketjoint in accordance with claim 39, further comprising grease disposedbetween said teeth and said corresponding surface contour of saidhousing to achieve easier assembly and better sealing action.
 46. A balland socket joint in accordance with claim 39, wherein said surfacecontour corresponding to a contour of said teeth includes housing teethand additional teeth of an additional sealing ring, said housing teethand said additional teeth being coated with a sealing and/or lubricatingmaterial or made of that material by injection molding or vulcanizationin one piece.